Web-based television

ABSTRACT

In a transmission system, a web site ( 90 ) stores information parts for providing additional information and/or functionality for corresponding content parts of a transmitted title. The content parts are identified in a predetermined addressing format for storage (“content part address”) on a removable storage medium. The receiver ( 60 ) receives linking information linking the transmitted title to the web site, and a data file including data associating, for respective content parts of the title, the corresponding content part address with a content part timing that identifies the content part in a transmitting timing format. A controller ( 250 ) of the receiver uses the linking information and the data file to, synchronous to the receiver supplying content parts of the transmitted title for rendering, enabling linking to the corresponding information parts on the web site.

FIELD OF THE INVENTION

The invention relates to web TV, where the receiver can obtainadditional information for a transmitted title by linking to a web site.

BACKGROUND OF THE INVENTION

New forms of consumer electronics products are continually beingdeveloped. Many efforts have been focused on the convergence of computertechnology and home entertainment systems that center on the television(TV) set. Important areas are interactive television and enhancedfunctionality, by merging broadcast television and Internet. WO 01/11874describes a system wherein WWW uniform resource locators (URLs) aresimulcast with TV signals. For example, URLs may be included into thevertical banking interval (VBI) of a broadcast TV signal or in aseparate data channel of a digital TV video stream. When prompted by amessage in the TV broadcast, the user may select one or more of the URLsto contact a web site over Internet and perform a transaction or obtainadditional information relating to the broadcast. Such information may,for example, be information on the actors, directors, etc.

WO 01/1 1874 further describes that the broadcast receiver also includesa storage device. If the user wants to access the web site, display ofthe broadcast is temporarily halted and the web content is displayed onthe screen. The broadcast title is in the mean time recorded in thestorage device and display of the title is continued from storage whenthe user has finished accessing the web.

A drawback of the known web TV system is that a considerable effort isrequired for each broadcast title to enhance the title with attractiveweb-based content

SUMMARY OF THE INVENTION

It is an object of the invention to provide an enhanced web TV system.

To meet the object of the invention, the transmission system includes atleast one receiver, a transmitting system for transmitting a title tothe receiver, and a web site for storing information parts for providingadditional information and/or functionality for corresponding contentparts of the title; the respective content parts of the transmittedtitle being identified in a predetermined addressing format for storageon a removable storage medium; the receiver being operative to receive:the transmitted title, linking information linking the transmitted titleto the web site, and a data file including data associating, forrespective content parts of the title, information identifying thecontent part in the addressing format for storage (hereinafter “contentpart address”) with information identifying the content part in atransmitting timing format (hereinafter “content part timing”); and thereceiver including a controller for, under control of a conversionapplication, synchronous to the receiver supplying content parts of thetransmitted title for rendering where the content parts are identifiedusing the content part timing, enabling linking to the correspondinginformation parts on the web site indicated by the linking information,using the data file to, based on the content part timing of thetransmission, determine the content part address, and/or based on thecontent part address determine the content part timing.

WO 00/63915 describes a system that integrates a DVD system with a WWWweb browser. Universal Resource Locator (URL) information correspondingto sites accessible by the browser is stored in fields within the DVDdata When the user actuates a DVD element that has a corresponding URL,the web browser displays information from that site. When the useractuates an HTML menu or other browser-implemented feature, the DVDsystem accesses a portion of the DVD data specified in the menu. Thisarrangement provides for two-way communication, i.e. HTML in the browseris able to control DVD content and vice versa. Having a link between theweb information and the DVD content makes it possible to present webcontent synchronous with the rendering of DVD information.

According to the invention, it is enabled to transmit a title, such asthe described DVD title, to a receiver and present the web informationsynchronous to rendering the received title. To this end, linkinginformation is provided to the receiver to enable a browser in thereceiver to locate the web site. It should be noted that web content onthe original web site is linked to content parts of the title on thestorage medium (e.g. the DVD), where the content parts are identifiedusing an addressing scheme defined for the removable storage medium(e.g. the DVD addressing scheme). The content parts of the transmittedtitle are identified using a suitable broadcast time stamp scheme. Toenable the receiver to use the web content, according to the invention aconversion table is provided to the receiver that enable the controllerof the receiver to convert one form of identification to the other form.The direction of mapping may be optimally chosen for the specificsystem. For example, in some systems or for certain titles, presentationof the additional web-based information may be primarily driven by thepresentation of the title (i.e. the title is rendered and the webcontent is retrieved when required for the rendering of the title). Inthis case, for many content parts (identified in the addressing format)links to web content may be provided. During the rendering of the title,for content parts identified in the timing format the provided table maybe used to determine the addressing format and use that format todetermine the link. In a preferred embodiment, most weight is given tothe web site for controlling the rendering. In such an approach it iseasier to subsequently develop the site further and to improve the website. In such a scenario, emphasis is given on processing the web site,where for much of the additional information parts on the web site it isindicated to which part of the content (in the addressing format) itrelates. The controller can then use the provided data file to convertthe content part address to the content part timing to enablesynchronous rendering.

In the system according to the invention, web sites developed for storedcontent can be re-used by once developing a conversion application to beexecuted by the receiver, where for each title only a conversion tableneeds to be created. In this way, web enhanced transmissions can becreated very fast for all content, like movies, for which thesignificant effort of enhancing the content has already been done forthe purpose of distributing the title on the removable storage medium.

Preferably, the title is being broadcast by the transmitter to thereceiver (and all other receivers in the system). The title may also bemulticast, i.e. sent in one simultaneous operation to a plurality ofreceivers (but usually not all) that have been selected for receipt. Forexample, only those receivers that have paid for receipt. In principle,the title may also be directly transmitted to the receiver, e.g. byaddressing it to the receiver or using a dedicated link.

As described in the dependent claim 2, some parts of the original titleas made for distribution on the storage medium may be removed from thetransmitted title (e.g. to reduce the length). To avoid that web-basedcontent is rendered for parts not present in the transmitted title, thedata file includes information that enables the controller in thereceiver not to render such web content.

As described in the dependent claim 3, also content parts may be addedto the transmitted title that were not present in the original storedversion of the title. For the additional content parts, also web-basedcontent may be made available through a different (or the same) website.

As described in the dependent claim 4, the conversion applicationprogram is pre-stored in the receiver. Since, according to the inventionthe application needs to be developed only once, it can be pre-stored.This enables optimal, platform specific coding of the application,reducing costs.

As described in the dependent claim 5, the transmitter provides theconversion application, for example in the form of an Xlet (Javaapplication optimized for a broadcast receiver platform). In this way,it is possible to control distribution of the application, for exampleto paying customers, and to easily update the application. A majoradvantage is that for most platforms, like MHP, a framework fordistribution and working of such applications has been defined. By usingsuch framework, no further standardization activities are required,which normally are required for interaction between a transmitter andreceiver.

As described in the dependent claim 6, the receiver downloads theapplication from a web site, for example, from the web site includingthe enhanced content or the web site of the manufacturer of thereceiver. Particularly, downloading via the web site with the enhancedcontent enables increasing the functionality of the application in linewith the functionality provided by the web site.

As described in the dependent claim 7, the data file (and optionallyalso the linking information) may be combined with the conversionapplication, for example forming one integrated Xlet. In this way theapplication and the conversion data can be optimally matched, althoughusually coming at an increased cost compared to only newly providing theconversion data.

As described in the dependent claim 8, the transmitting systembroadcasts the data file and/or the linking information. This is aneffective way of distributing the data to several receivers whilekeeping the load on the transmitting medium to a minimum.

As described in the dependent claim 9, in the receiver or attached tothe receiver a storage system is used for recording the transmittedtitle. Also the linking information and data file are recorded. Thisenables subsequent rendering from the local storage. Moreover,additional functionality that is not possible during a real-timetransmission can be made available. For example, VCR or DVD-like menu'scan be made available that enable a user to continue the rendering froma previous location (such as a DVD chapter), to pause playback, andperform winding/rewinding functions. To this end, the receiverdetermines whether the title is provided in real-time or from storage.For rendering from storage more functionality is made available.

These and other aspects of the invention are apparent from and will beelucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a block diagram of a digital broadcast system wherein theinvention can be used;

FIG. 2 shows a block diagram of a receiver for use in the system; and

FIG. 3 shows an example of a data file according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 gives an overview of a digital television system in which thereceiver according to the invention can be used. As an example, a systemis described wherein the audio/video (A/V) signals are distributeddigitally using MPEG-2 compression to compress the A/V signals. Thesystem includes an MPEG-2 compressor 10, usually located in a broadcastcentre. The compressor receives a digital signal stream (typically astream of digitized analog or digital video signals). The originalsignals are supplied by a service provider. The compressor is connectedto a scrambler and multiplexer 20. The scrambler scrambles the digitalsignals of a data stream by encrypting them under control of a contentkey, as will be described in more detail below. The multiplexer 20 mayreceive in addition to one or more scrambled or non-scrambled datastream also further digital signals. The multiplexer 20 assembles allthe signal and streams into a transport stream and supplies thecompressed and multiplexed signals to a transmitter 30 of the broadcastcentre. The scrambling and multiplexing functions may be performed inseparate units, and if desired at different locations. The multiplexedtransport stream may be supplied from the scrambler/multiplexer 20 tothe transmitter 30 using any suitable form of linkage, includingtelecommunication links. The transmitter 30 transmits electromagneticsignals via an uplink towards a satellite transponder 40, where they areelectronically processed and broadcast via a downlink to an earth-basedsatellite receiver 50, conventionally in the form of a dish of the enduser. In the figure, the satellite receiver 50 is connected to anintegrated receiver 60. The operation of the receiver 60 is described inmore detail below with reference to FIG. 2. The receiver selects thedesired signal and presents it in a suitable form to a rendering device,such as a television 70. The signal may also be recorded using a tape,optical disc or hard disk recorder or other suitable recorder. Thesignal may be supplied to the rendering/recording device in an analog ordigital form using well-known distribution systems such as CATV cable,or IEEE 1394. For digital distribution only partial decoding of thetransport stream is required, where the de-multiplexed signals aresupplied in the MPEG-2 coding using partial transport streams. It willbe understood that the main distribution of the AV signals does not needto take place via satellite. Instead other delivery systems (i.e. thephysical medium by which one or more multiplexes are transmitted) may beused, such as terrestrial broadcast, cable transmission, combinedsatellite/cable. The party that distributes the program via the deliverysystem is sometimes referred as the network provider. It will also beunderstood that the receiver/decoder 60 may be integrated into therendering or recording device.

A typical system operates as a multi-channel system, implying that themultiplexer 20 can handle A/V information received from a number of(parallel) sources and interacts with the transmitter 30 to broadcastthe information along a corresponding number of channels or multiplexedinto separate transport streams. In addition to A/V signals, messages orapplications or any other sort of digital data may be introduced in someor all of these services/channels interlaced with the transmitteddigital audio and video information. As such a transport stream includesone or more services, each with one or more service components. Aservice component is a mono-media element. Examples of servicecomponents are a video elementary stream, an audio elementary stream, aJava application (Xlet), or other data type. A transport stream isformed by time-multiplexing one or more elementary streams and/or data.

Preferably, bi-directional communication is enabled in the system tofacilitate interactive applications, such as interactive video,e-commerce and so on, and to enable the receiver to obtain additionalinformation/functionality from the web site. Shown is the use of a widearea network 80, preferably the open Internet, where the addedfunctionality and interactivity is provided by a web site on a webserver 90. To enable broadcasting or multicasting of data orapplications stored on the web site, preferably, the web server 90 alsohas a connection to the multiplexer 20. This may be a direct link butmay also be via the Internet. It will be understood that thecommunication functionality of Internet or similar communication systemmay be provided in any suitable form. For example, the receiver maycommunicate via a cable network or satellite connection, directly usingInternet protocols. Alternatively, the receiver may have atelephone-based dial-in connection to an access provider that providesaccess to the Internet. The receiver may, but need not use Internetprotocols. If the server 90 does use Internet protocols, protocolconversion may take place, for example using a gateway.

Although the system according to the invention is described for adigital broadcast system, in principle the invention can also be appliedfor non-broadcast transmissions. For example, the same concepts can beapplied easily where a title is supplied to individual receivers, forinstance on a pay-per-view basis. The transmission may then take placevia a typical broadcast system (but directly addressed) or via othersuitable systems, such as a high-bandwidth Internet connection.

FIG. 1 also shows a removable storage medium, such as CD-ROM, DVD, orsolid state memory, which stores AV data. Typically, the AV title is amovie or similar AV data for which enhanced functionality has alreadybeen developed once. Usually, the title was stored in a compressed form,for example using MPEG-2 coding. For transmission, the title may bechanged, for example some parts may be removed, for example to reducethe length, and some other part, like commercials, may be added.Consequently, the title will usually be re-coded. Using the exemplarydigital transmission system of FIG. 1, this is shown by feeding thetitle through the coder 10. The title will anyhow be multiplexed intothe transport stream by the multiplexer 20. Of course, the title neednot be taken from the storage medium 95 but may also in an originalversion be supplied by a studio.

For the title, enhanced functionality has been made available via theInternet through a web site. The web site may, but need not be the same,as the one used when transmitting the same title. The original web sitecontains many additional information parts, of which some have a clearcorrespondence with content parts of the title. For example, the website may include more subtitles or languages than the original title onthe storage medium 95. For example, a DVD may have been supplied indifferent versions for different regional areas. As the differentversions are developed more languages and sub-titles may be developed aswell. Whereas a DVD typically includes 3 or 4 languages and sub-titlesin up to 8 languages, the additional information can be added to the website. For example, this would enable a Dutch viewer in the US to viewthe DVD with the US region code (and not including Dutch language andDutch sub-titles) in Dutch. It will be understood that the web site thencontains information on synchronizing (“linking”) the information on theweb site to corresponding content parts of the title. In theory, suchlinking information can also be embedded in the DVD, but it is preferredto let the web site couple the web information to the content in orderto be more flexible. As a further example, after the DVD has beencompleted (and distributed) more functionality may be added, for examplean interview with the director, script writers, or actors may be storedon the web site, where parts of the interview link to content partsbeing discussed. In this way, the viewer watching the interview(retrieved from the web site) can also view the content parts beingdiscussed. Similarly, games and quizzes may be developed and madeavailable through the web site that may or may not link web-basedcontent to the title content. Further examples of enhanced functionalityare:

-   -   Enhanced menu structures (compared to the original menus on the        DVD)    -   E-commerce, buying items related to the movie    -   Promotion of similar/related movie titles    -   Provide up-to-date profiles of actors, directors, etc.

The web site may be based on a declarative approach. In such an approachthe web site does not contain actual program code but instead describesthe type of content and the connections (links) between the contentparts. Such a web site could be based on HTML, XML or similardescriptive languages. The web site may also be based on a moreprocedural approach. In this approach an Application ProgrammingInterface (API) has been defined for the receiver for accessingfunctions of the receiver (including controlling the content received bythe receiver), for example similar to a Java Virtual Machine.

FIG. 2 shows more details of a typical broadcast receiver. The broadcastreceiver, preferably, complies with a defined platform like the EuropeanMHP (Multi-media Home Platform) or the US DASE platform. The broadcastreceiver includes a tuner 210. The tuner 210 extracts a separate tunableRadio Frequency (RF) band usually resulting in an MPEG2 transportstream. Variable data signals are separated from the constant carriersignal by the de-multiplexer 220 (De-MUX). The results often are audio,video and data outputs. The video and audio streams may be fed through aConditional Access subsystem 230, which determines access grants and maydecrypt data. The audio and video streams are fed to a decoder 240,which converts them into signals appropriate for the video and audiorendering or storage devices. This may involve MPEG2 decoding. Thereceiver also includes the communication interface 280 forbi-directional communication to the web site. Any suitablecommunications hardware/software may be used for this, includingconventional modems for standard telecommunication lines or broadbandmodems. The bidirectional communication channel facilities interactiveapplications, such as interactive video, e-commerce and so on, andobtaining additional information/functionality from the web site on theweb server 90 of FIG. 1. Preferably, Internet protocols are used, forexample those defined in the MHP “Internet Access Profile”. The relevantdata retrieved from the web site will be converted by a converter 260(such as an audio D/A converter and a graphics processor) to a suitableform for presentation to a user, for example via a loudspeaker and/orvideo display. The video may be combined with the video generated by thedecoder 240 into one frame buffer 270. In this way, the web-data may beoverlaid (e.g. as sub-titles, or as a Picture-in-Picture), or mixed withthe video signal. Output of the decoder can be supplied to a renderingdevice or storage device for subsequent rendering. Shown is an internalstorage 290. Typically, the output is first stored in a frame buffer 270for subsequent supply to the rendering/storage device. For certainapplications, the receiver may provide encoded output streams, bypassingthe decoder 250. The rendering device may then include the decoderfunction or the encoded stream may at a later stage be re-supplied tothe receiver for further decoding. The encoded data stream may also berecorded in the storage 290 for subsequent rendering. A user interface295 of the receiver enables the receiver to interact with the user. Theuser interface 295 may include any suitable user input means, such as anInfrared receiver for receiving signals from an IR remote control, akeyboard, or a microphone for voice control. For output, also anysuitable form may be used, such as using a small LCD display or usingthe display of a television, or even audible feedback.

It will be appreciated that the various functions, such as the tunerfunction 210, the de-multiplexer function 220, the optionaldescrambler/decryptor function 230, and the decoder function 240 may beperformed using dedicated hardware. Some functions or part of thefunctions may also performed by a programmable processing function, forinstance using a digital signal processor (DSP) loaded with a suitableprogram. The various functions within the receiver are operated undercontrol of the controller 250, which typically includes an embeddedmicroprocessor or microcontroller. To keep the figure simple, thecontrol relationship between the controller and the other functions arenot shown. Only the roles that the controller can have in processing ofthe web data and synchronizing the presentation of AV content and webcontent are shown. For presenting the web content, the controller mayexecute an application similar to web browsers known from PCs. It willbe appreciated that for certain information a much simpler applicationmay be used. For example, sub-titles retrieved from the Internet can beoverlaid in a way that Teletext sub-titles are overlaid. The user needsnot to be aware that the actual added content is retrieved from the web.

According to the invention, the receiver is provided with linkinginformation, and a data file. This information is used by a specialapplication program “a conversion application”.

The linking information enables the controller (under control of theapplication) to locate the web site with the additional information. Ina preferred embodiment, the linking information is relatively simple.For example, the linking information could include the following threelinks:

-   -   1. Synchronous features http:// . . . / . . .    -   2. Additional information http:// . . . / . . .    -   3. Storage only features http:// . . . / . . .

The first link is preferably always present. It enables locatingadditional information that needs to be rendered synchronous withrendering of parts of the title. A separate link (link 2) may beprovided for feature that do not require synchronous rendering of theweb content and the AV content, for example an actor's biography. Thisadditional link for non-synchronous features may be directed to anotherweb site or to a sub-part of the same web site. The non-synchronousfeatures may but need not have been available for the original storedtitle. If the title is recorded at the location of the receiver (e.g.using a hard disc or recordable optical storage in or connected to thereceiver), more advanced features may become available. For example,menus supporting selection of freely selectable parts of the title, fastforwarding, rewinding type of functions may become available. Also adirector's commentary may be intermixed with display of the scenes beingdiscussed. Such features are preferably accessible via the third link. Asignal is provided to the controller 250 if the title is reproduced froma local storage (such as the internal storage 290 of FIG. 2) so that thecontroller can enable use of the additional functionality provided viathe third link. In these examples it is assumed that detailed linking asidentified parts of the title content or web content is managed by theinformation on the site. In such a case, the linking informationprovided to the receiver initially can be high-level, where the detailedlinking will occur while processing the web based data.

In order to understand the data file and the conversion application,first a description is given of relevant information of a web-enhancedtitle distributed on a removable storage medium. Here as an example, DVDwill be described. DVD-Video defines navigation data to controlplayback. This logical structure defines the following units (amongothers): Unit Maximum Title  99 per disc Program Chain (PGC) 999 pertitle Part of Title (PTT) 999 per title, 99 per sequential PCG titleProgram (PG)  99 per Program Chain (PG)

The meaning of these units is as follows:

-   -   Title—movie, TV program or music album    -   Program Chain—collection of programs or groups of cells linked        together to create a sequential presentation    -   Program—group of cells within a program chain (PGC)    -   Part of title (PTT)—a division of a title representing a scene,        also called a chapter

For example a DVD-Video disc could contain a single title (the movie)with multiple Program Chains (for different version of the movie). Thetitle is also split into parts (PTTs) which correspond to what the userthinks of as chapters.

Also DVD-Video defines commands for controlling playback (Annex J of theDVD specification) which in some cases will correspond to remote controlcommands. These commands control playback using the units defined above.Some sample commands are:

-   -   Title_Play (Title number)—Play title    -   PTT_Play (Title number, PTT number)—Play PTT within the title    -   Time_Play (Title number, Time)—Play title at a specific time    -   PTT_Search (PTT number)—stop current presentation and start        presentation from the beginning of PTT number specified.

The web site developed for the DVD may include features that playbackspecific parts of the content in non-linear order. The description ofthese features (whether procedural or declarative) will use the DVDAnnex J commands to control playback. For stored content these featurescan be used within MHP (or similar platform) controlling playback.

The web site may also contain content that is presented along with themain video presentation e.g. subtitles, foreign language soundtrackscript and directors notes while video displayed on part of the screen.This content will need to be synchronized with the DVD-Video and stayconsistent with the video content even with user operations such as fastforward/rewind, next/previous chapter. These features can be presentedto the user during a TV broadcast without requiring the content to bestored.

In both cases it is necessary to have a mapping between the logicalnavigation structure on the DVD and the timing in the broadcast. In apreferred embodiment, this takes into account the possibility that themovie has been edited for TV so parts have been deleted or that extracontent has been added to the broadcast (e.g. commercial breaks, moviesplit with news bulletin).

MHP defines Normal Play Time (NPT) which is included in the TransportStream and accessible to the applications. It provides a continuousmonotonically increasing time base independent of any timingdiscontinuities in the broadcast NPT does not need to be included in abroadcast but is part of MHP and so can be used in this case to definethe time relation between the DVD content and the broadcast. The NPT canalso be paused for some time e.g. during a commercial break the NPT ofthe main programme will pause. There may be multiple NPTs in thebroadcast but only one can be increasing at any point in time e.g. theNPT of the main programme may be paused during an inserted news bulletinduring which a separate NPT will increase. Essentially, the NPT is anoffset from the Transport Stream timing (based on PCR) but withoutdiscontinuities. PCR is an acronym from MPEG-2 Transport Stream. Itstands for Program Clock Reference and it is the basic timing in theTransport Stream along with the PTS/DTS times (Presentation Time Stampand Display Time Stamp). The PCR is repeated in the Transport Stream(e.g. every 100 ms) to give the current time and the PTS/DTS refer tothe same timebase as the PCR.

The data file according to the invention provides a mapping from theDVD-Video presentation structure (or more generally: the addressingstructure used for identifying the stored content part) to be broadcast,where content parts are identified using broadcast timing information.The details of how this is coded are not important (e.g. using XML) butthe data file does define for the content parts of the original storedtitle that are present in the broadcast the time relation between thetwo. In a preferred embodiment, the data file also defines which partsof the DVD content are present in the broadcast (or, reversely, are notpresent in the broadcast) to enable the controller to disable renderingor information parts on the web site that relate to removed contentpart.

FIG. 3 shows an example of the data file mapping the content partaddress of DVD (indicated in column 310) to the content part timing(indicated in column 320) in the MHP NPT format In the example, title 1is divided in seven chapters PTT1 to PTT7. Chapter PTT5 is removed fromthe broadcast. In the exemplary data file, it is removed from the datafile. It will be understood that it may also still be present in thetable, where in column 320 it is made clear that it is not present inthe broadcast (e.g. by having no value in column 320). As such the datafile indicates explicitly or implicitly which content parts of the titlehave been removed from the broadcast. Based on such information, thecontroller can disable rendering of any web-based content that relate tocontent parts not present in the broadcast/transmitted title. Further,it can be noted that there is a gap in the broadcast content compared tothe original stored title: PTT 3 starts at timing NPT3 whereas theprevious chapter ended at broadcast time NPT2. This gap may be becauseadditional content, like a commercial, has been added in the broadcastthat was not present in the original stored content. In the example,also title 3 has been removed in its entirety. Persons skilled in theart will be able to adapt the data file for other storage formats andother broadcast timing formats. As an example, the storage addressingmay also be at a more detailed level than chapters, for example at DVDcell level.

The above structure takes the DVD structures and indicates which partsare in the broadcast. Of course an alternative structure would be tostart with the broadcast content timeline and indicate for each partwhich part of the DVD it corresponds to. Depending on what level the website content references the DVD it may be sufficient to store a subsetof this mapping e.g. if the web site doesn't reference Programs (PGs)then there is no need to store the mapping to PGs.

Other systems than MHP may not use the NPT principle, but may havesimilar mechanisms. If no suitable mechanisms are present, instead amapping can be given to the timing in the broadcast (based on PCRs)taking into account possible discontinuities. Of course this timeinformation must be available to the Interactive application.

It will also be appreciated that the broadcast may add content for whichalso support is provided on the web site. Such new content parts need tobe identified, for example mimicking the DVD addressing format.Preferably, the new parts are not identified using the transmissiontiming format. By using a format independent of the transmission, it ismade easier to re-use the added content for othertransmissions/broadcasts that may use a different transmissionidentification. The conversion data file includes also conversion datafor the added content parts.

In a preferred embodiment, the receiver stores the transmitted title ina storage, such as the internal storage 290 of FIG. 2. In storing atransmitted title, typically also a mapping from the broadcast timing tolocations on storage, such as a recordable disc, is stored. This allowssupport for jumping a certain time within the programme and trickplay(for many applications it may be sufficient to store time/location forMPEG-2 I-frames). This additional mapping enables finding a location inthe storage based on the timing in the broadcast. For this invention,the web site would indicate a locations based on, for example, the DVDaddressing. The data file indicates a mapping to the broadcast timingand then using the new storage locations it is possible to map againfrom the broadcast timing to actual locations on disc. If so desired, itis possible to update the data file to provide a direct mapping from theDVD addressing to the addressing on the new storage.

As will be understood, the conversion application needs to be developedonly once. It can be pre-stored in a read-only memory (such as ROM) andloaded into the controller when required. It may also be stored in awriteable memory, like flash memory, hard disc, or rewriteable storage.In such a case, it may be received via distribution on a medium like aCD-ROM, it may be transmitted via a communication system like Internet(preferably downloaded from the web site that corresponds to the titleor a web site of the set maker), or it may be broadcast by the AVbroadcast system, for example as a Java applet (Xlet) in the multiplexedtransport stream. It may also be multi-cast to selected receivers, forexample those that have subscribed to a particular service. Similarly,the data file and linking information may be retrieved via the Internet(or other communication system), or multi-cast/broadcast by the AVtransmission system.

To avoid that the web site for a once recorded title at the moment ofrendering of the title is no longer available, in a preferred embodimentthe relevant content on the web site is also recorded locally undercontrol of the receiver, for example in storage 290 of FIG. 2. The AVtransmitting system preferably broadcasts the web content. If sodesired, it may also be directly addressed to an individual receiver ormulti-cast to a group of receivers.

It should be noted that the above-mentioned embodiments illustraterather than limit the invention, and that those skilled in the art willbe able to design many alternative embodiments without departing fromthe scope of the appended claims. In the claims, any reference signsplaced between parentheses shall not be construed as limiting the claim.The words “comprising” and “including” do not exclude the presence ofother elements or steps than those listed in a claim. The invention canbe implemented by means of hardware comprising several distinctelements, and by means of a suitable programmed computer. Where thesystem/device/apparatus claims enumerate several means, several of thesemeans can be embodied by one and the same item of hardware. The computerprogram product may be stored/distributed on a suitable medium, such asoptical storage, but may also be distributed in other forms, such asbeing distributed via the Internet or wireless telecommunicationsystems.

1. A transmission system including at least one receiver, a transmittingsystem for transmitting a title to the receiver, and a web site forstoring information parts of providing additional information and/orfunctionality for corresponding content parts of the title; therespective content parts of the transmitted title being identified in apredetermined addressing format for storage (hereinafter “content partaddress”) on a removable storage medium; the receiver being operative toreceive: the transmitter title, linking information linking thetransmitted title to the web site, and a data file including dataassociating, for respective content parts of the title, thecorresponding content part address with a content part timing thatidentifies the content part in a transmitting timing format; thereceiver including a controller for, under control of a conversionapplication, synchronous to the receiver supplying content parts of thetransmitted title for rendering where the content parts are identifiedusing the content part timing, enabling linking to the correspondinginformation parts on the web site indicated by the linking information,using the data file to, based on the content part timing of thetranmission, determine the content part address, and/or based on thecontent part address determine the content part timing.
 2. A system asclaimed in claim 1, wherein the web site includes information partsrelating to removed content parts not present in the transmitted title,but available for distribution on the removable storage medium, the datafile indicating the removed content parts; and the controller beingoperative to disable rendering of information parts on the web site thatrelate to removed content parts.
 3. A system as claimed in claim 1,wherein a further web site includes additional information partsrelating to additional content parts present in the transmitted titlebut not available for distribution on the removable storage medium; andthe linking information also linking the transmitted title to thefurther web site to enable the controller to render the additionalinformation parts synchronous with the receiver supplying the additionalcontent parts for rendering.
 4. A system as claimed in claim 1, whereinthe conversion application is pre-loaded in a memory of the receiver. 5.A system as claimed in claim 1, where the transmitting system isoperative to provide the conversion application to the receiver bytransmitting it directly addressed to the receiver or by broadcasting itto a plurality of receivers.
 6. A system as claimed in claim 1, whereinthe receiver is operative to download the conversion application from aweb site.
 7. A system as claimed in claim 5, wherein the conversionapplication includes the data file.
 8. A system as claimed in claim 1,where the transmitting system is operative to broadcast the data fileand/or the linking information.
 9. A system as claimed in claim 1,wherein the receiver is operative to store the transmitted title,linking information, and data file in a local storage system; the datafile further including information on information parts (hereinafter“storage-only parts”) on the web site only available when rendering thetitle from storage; the conversion application being operative to causethe controller to determine whether the title is rendered from a livetransmission or from storage and to enable rendering of the storage-onlyparts on the web site only for rendering of the title from the localstorage system.
 10. A system as claimed in claim 9, wherein the receiveris operative to store the information on the web site in the localstorage system; the conversion application being operative to cause thecontroller to render, for a title rendered from storage, thecorresponding web site information from the local storage system.
 11. Asystem as claimed in claim 10, wherein the transmitter is operative toprovide the information on the web site to the receiver by transmittingit directly addressed to the receiver or by broadcasting it to aplurality of receivers.
 12. A receiver for use in the system as claimedin claim 1, the receiver being operative to receive: a title transmittedby a transmitter; linking information linking the transmitted title to aweb site for storing information parts for providing additionalinformation and/or functionality for corresponding content parts of thetitle; the respective content parts of the transmitted title beingidentified in a predetermined addressing format for storage (hereinafter“content part address”) on a removable storage medium; and a data fileincluding data associating, for respective content parts of the title, acorresponding content part address with a content part timing thatidentifies the content part in a transmitting timing format; thereceiver including a controller for, under control of a conversionapplication, synchronous to the receiver supplying content parts of thetransmitted title for rendering where the content parts are identifiedusing the content part timing, enabling linking to the correspondinginformation parts on the web site indicated by the linking information,using the data file to, based on the content part timing of thetransmission, determine the content part address, and/or based on thecontent part address determine the content part timing.
 13. A computerprogram product for causing a controller in a receiver to: processlinking information linking a received title to a web site for storinginformation parts for providing additional information and/orfunctionality for corresponding content parts of the title; therespective content parts of the received title being identified in apredetermined addressing format for storage (hereinafter “content partaddress”) on a removable storage medium; process a data file includingdata associating, for respective content parts of the title, acorresponding content part address with a content part timinginformation that identifies the content part in a transmitting timingformat; and synchronous to the receiver supplying content parts of atitle received from a transmitter for rendering where the content partsare identified using a content part timing of the transmission, enablinglinking to information parts on a web site that correspond to thecontent parts, where the web site is indicated by linking information,using the data file to, based on the content part timing of thetransmission, determine a content part address, and/or based on thecontent part address determine the content part timing.